N-substituted fatty acid amide lubricants

ABSTRACT

THIS INVENTION RELATES TO N-ACYLMORPHOLINES AND NMONO AND N,N-DISUBSTITUTED FATTY ACID AMIDES AND TO SIMILAR DERIVATIVES OF EPITHIOAMIDES WHICH ARE USEFUL AS BASE AND EXTREME PRESSURE LUBRICANTS AND ADDITIVES.

United States Patent Office 3,801,609 Patented Apr. 2, 1974 U.S. Cl.260-4025 1 Claim ABSTRACT OF THE DISCLOSURE This invention relates toN-acylmorpholines and N- mono and N,N-disubstituted fatty acid amidesand to similar derivatives of epithioamides which are useful as base andextreme pressure lubricants and additives.

This is a division, of application Ser. No. 176,734, filed Aug. 31,1971, now Pat. No. 3,746,644.

A non-exclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purposes of the UnitedStates Government, with the power to grant sublicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This invention relates to certain compounds which are N-fatty acylderivatives of primary and secondary amine and N-substituted acylderivatives of primary and secondary amines which have exhibited utilityas base lubricants, extreme pressure lubricants or lube additives. Moreparticularly, this invention relates to N- and N,N-disubstituted longchain aliphatic amides the acyl component of which is a normal,branched, or substituted alkenoic or alkanoic acyl group containing from16 to 22 carbon atoms the amide nitrogen of which may be derived from analkyl amine, dialkyl amine, alkylalkoxyalkylamine, dialkoxyalkylamine ornitrogen heteroalicyclic. Typical amines are butylamines, dibutylamines,N-methyl-alkoxyethyl amine, di-ethoxyethyl amine, and morpholine. Theacyl substituent referred to may be divalent sulfur or pentavalentphosphorous.

We have discovered that many of the simple N-alkyl and N,N-dialkyl rN-alkyl-N-alkoxyalkyl amides of the C to C alkeneoic or alkanoic fattyacids are good base lubricants. We have further discovered that theintroduction of divalent sulfur into the fatty acid moiety impartsexcellent extreme pressure lubricant characteristics to such compounds.In particular we have found the epithio group to be most effective. Wehave also observed that the introduction of both hydroxy and alkylphosphato groupings alpha to each other also imparts extreme pressurelubricant characteristics to the compound.

In addition it was noted that the above hydroxy-phosphato compound andits mercapto analog N-[9(10)-mercapto-(9) IO-dibutylphosphato]stearamidewere effective antiwear compounds and additives.

Included among the specific compounds operable as base lubricants are Nmethyl-N-butyloleamide, N-ethoxyethoxyethoxy propyloleamide,N-ethoxyethoxy propyloleamide, N-methoxyisopropyloleamide,N-methoxyethyloleamide. Compounds showing particular promise as extremepressure lubricants or additives are N,N-dibutyl-9,10-epithiostearamide,N,N dibutyl-9,10-12,13-diepithiostearamide, 9,10-epithiostearoylmorpholine, N-ethoxyethoxyethoxypropyl 9,10 epithiostearamide,N-9,10-12,13-diepithiostearoylmorpholine and N-[9(10)-hydroxy-9(10)-dibutylphosphato]stearamide.

Compounds showing particular promise as antiwear additives areN,N-dibutyl-[9(10)-hydroxy-(9)IO-dibutylphosphato] stearamide andN,N-[9(10) mercapto-(9) 10- dibutylphosphatostearoyl]morpholine.

EXAMPLE 1 N-rnethyl-N-butyloleamide.- grams (0.33 mole) of oleoylchloride was added dropwise and with stirring to a mixture of 29 grams(0.33 mole) of N-methyl-N-butylamine and 27 grams (0.33 mole) ofpyridine. Stirring was continued until the heat of reaction subsided.The solid pyridine hydrochloride was filtered off and the filtrate waswashed successively with aqueous HCl and water until acid free. It wasdried, stripped, percolated through an activated alumina column, and theproduct removed from the percolate by stripping off the solvent.Analysis of the product: Percent C, 78.87 (theory 78.63); percent H,13.02 (theory 12.82); percent N, 3.96 (theory 3.99).

EXAMPLE 2 N,N-dibutyloleamide.--This material was prepared by theprocedure of Example 1 from 100 grams (0.33 mole) of oleoyl chloride42.5 grams (0.33 mole) of di-nbutylamine and 27 grams (0.33 mole)pyridine. Analysis of the product: Percent C, 78.94 (theory 79.25);percent H, 13.16 (theory 13.06); percent N, 3.44 (theory 3.56) confirmthe preparation.

EXAMPLE 3 Ethoxyethoxyethoxy propylo1eamide.This material was preparedby the procedure of Example 1 from 100 grams (0.33 mole) of oleoylchloride, 73.0 grams (0.33 mole) ethoxyethoxyethoxypropylamine and 27.0grams (0.33 mole) pyridine. Analysis of percent C, 71.84 (theory 72.04);H, 11.80 (theory 11.80), and N, 2.96 (theory 2.90) confirm thepreparation.

EXAMPLE 4 Ethoxyethoxypropyloleamide.-This material was prepared by theprocedure of Example 1 from 100 grams (0.33 mole) of oleoyl chloride,58.3 grams (0.33 mole) ethoxyethoxypropylamine and 27.0 grams (0.33mole) of pyridine. Analyses of percent C, 71.45 (theory 73.80); percentH, 11.87 (theory 12.07); and percent N, 2.92 (theory 3.18) confirm thepreparation.

EXAMPLE 5 Methoxyisopropyloleamide.This material was prepared by theprocedure of Example 1 from 100 grams (0.33 mole) of oleoyl chloride,29.3 grams (0.33 mole) methoxyisopropylamine and 27.0 grams (0.33 mole)pyridine. Analysis of percent C, 73.15 (theory 74.99); percent H, 12.01(theory 11.93); and percent N, 3.67 (theory 3.97) confirm thepreparation.

3 EXAMPLE 6 Methoxyethyloleamide.-'Ihis material was prepared by theprocedure of Example 1 from 100 grams (0.33 mole) of oleoyl chloride,24.4 grams (0.33 mole) of methoxyethylamine and 27.0 grams (0.33 mole)pyridine. Analysis of percent C, 73.08 (theory 74.55); percent H, 11.98(theory 11.83); and percent N, 3.31 (theory 4.14) confirm thepreparation.

EXAMPLE 7 Oleoylmorpholine.-This material was prepared by the procedureof Example 1 from 100 grams (0.33 mole) of oleoyl chloride, 28.7 grams(0.33 mole) of morpholine and 27.0 grams (0.33 mole) of pyridine.

EXAMPLE 8 N,N-dibutyloleamide.-This product was prepared following theexact procedure of Example 2 except for the substitution of oleoylchloride by linoleoyl chloride.

EXAMPLE 9 N,N-dibutyl-9,10-epithiostearamide.-120 grams (0.30 mole) ofN,N-dibutyloleamide was epoxidized by the addition with stirring of 62.0grams (0.36 mole) of metachloroperbenzoic acid in 630 ml. of chloroform.Reaction was continued for 1 hour beyond final addition and the excessperacid destroyed by a small amount of a 10% solution of Na SO Themetachlorobenzoic acid was removed by a NaHCO wash, followed by waterwashing. The CHCl solution was then dried with anhydrous Na SO and theCHCl stripped off to recover the productN,N-dibutyl-9,10-epoxystearamide, oxirane content 3.45% (theory 3.91%).100 grams (0.24 mole) of this product was added to a Well stirred slurryof 55.7 g. (0.75 mole) of thiourea and 89.5 g. (0.72 mole) of benzoicacid in acetone. Stirring was continued for 3 hours beyond the terminaladdition whereupon the henzoic acid was washed out with 38.8 g. (0.36mole) of Na CO and the organic product extracted with hexane. Theorganic phase extract was dried and stripped to recover the product N,Ndibutyl-9,lo-epithiostearamide containing 6.41% sulfur (theory 6.67%).

EXAMPLE 10 N (9,10-epithiostearoyl)morpholine-This product was preparedby the exact procedure described in Example 9 except for thesubstitution of oleoylmorpholine for the N,N-dibutyloleamide of Example9. Analysis of product showed percent C, 71.22 (theory 69.34); percentH, 11.22 (theory 10.77); percent N, 3.66 (theory 3.68); percent S, 3.44(theory 7.80).

EXAMPLE 11 N,N dibutyl 9, 10-12, l3-diepithiostearamide.-This productwas prepared following the procedure described in Example 9 except forthe replacement of the N,N-dibutyloleamide of Example 9 byN,N-dibutyllinoleamide, and a doubling of the molar ratios of allreagents. The product analyzed as follows: percent C, 69.64 (theory68.57); percent H, 10.93 (theory 10.76); percent N, 3.10 (theory 3.07);percent S, 11.7 (theory 14.06).

EXAMPLE 12 N-ethoxyethoxyethoxypropyl-9, 10-epithiostearamide.- To 166g. of N-ethoxyethoxyethoxypropyl oleamide, Example 3, was added dropwiseand with stirring 73.8 g. of m-chloroperbenzoic acid in 800 ml. of CHClThe spent m-chloroperbenzoic acid was removed with 10% aqueous NaHCO andthe epoxide recovered by drying and stripping 01f the CHCl 171 g. ofthis epoxide was added dropwise to a slurry of 56 g. thiourea in 1000ml. of acetone and the concurrent addition of 43.4 g. of glacial aceticacid and the reaction mixture stirred for 3 hours. The glacial aceticacid was neutralized with Na CO and the episulfide,N-ethoxyethoxyethoxypropyl- 9,10-epithiostearamide, extracted withSkellysolve B and washed, dried, and stripped. Its elemental analysiswas C=67.1 (66.52), H=11.42 (10.88), N=2.67 (2.87), S=2.29 (6.57).

EXAMPLE 13 N ethoxyethoxyethoxypropyl 9(l0)mercaptostearamide.17 g. ofN-ethoxyethoxyethoxypropyloleamide in CCL, was treated in the cold witha CCl, solution containing 60.9 g. of bromine. Any unreacted bromine wasre moved by a thiosulfiate wash. 14 g. of the resulting dibromo compoundwas added dropwise to a well stirred solution of 72 g. of Na S-9H O indimethylsulfoxide maintained at C. Stirring was continued at 80 C. for 3hours. Water was added and the reaction product was extracted withhexane; washed, dried, and stripped. Elemental analysis of the productwas C=66.3 (66.5), H=11.1 (10.9), N=2.7 (2.9), S=4.4 (6.8).

EXAMPLE l4 N,N-dibutyl 9(10) [dibutylphosphono]stearamide. g. ofN,N-dibutyloleamide, Example 2, 148 g. of dibutyl phosphite, and 1.29 g.of benzoyl peroxide catalyst were heated at C. for 3 /2 hours.Additional units of 1.29 g. of benzoyl peroxide was added after thefirst and second hours of reaction time. The excess dibutyl phosphitewas then removed by distillation at reduced pressure, 0.45 mm. Hg. Thestillpot contents showed strong adsorption bonds at 8, 9.3, and 9.7microns characteristics of the phosphonate group. The elemental analysiswas C=obs 71.46 (69.50), H=obs 12.42 (11.92), N: obs 2.20 (2.38), P=obs4.24 (5.28) percent respectively.

EXAMPLE l5 N-9,10-1'2,13-diepithiostearoylmorpholine.--This' product wasprepared by the same procedure described in Example 9 except for thesubstitution of linoleoyl morpholine for the N,N-dibutyloleamide ofExample 8 and the doubling of molar proportions of them-chloroperbenzoic acid in the epoxidation step and the thiourea andbenzoic acid in the epithioation step. The elemental analysis was C=obs68.89 (63.92), H=obs 10.26 (9.44), N=obs 3.29 (3.38), S=obs 4.00 (15.49)percent re spectively.

EXAMPLE l6 N,N-Dibutyl- [9 10 -hydroxy- 9) 10-dibutylphosphato1-stearamide.44.7 g. of dibutylhydrogen phosphate was added to 182.2 g. ofN,N-dibutyl-9,10-epoxystearamide at 90-95 C. with stirring. Reactionconditions were continued for 3 /2 hours after termination of theaddition. The reaction product was dissolved in commercial hexane andthe unreacted dibutyl hydrogen phosphate neutralized and washed out withportions of aqueous 10 NaHCO followed by several water washes.Acidulation of the hexane phase with diluted HCl followed by severalwater washes, drying and stripping, yielded the product. Elementalanalysis was, C=obs 66.56 (65.91), H=obs 11.04 (11.30), N=obs 2.90(2.26), P|=obs 3.04 (4.20).

EXAMPLE 17 N [9(10)mercapto-(9) 10-dibutylphosphatostearoyl]morpholine.-12 g. of dibutylhydrogen phosphate was added dropwise withstirring to 51.0 g. of (9,10-epithiostearoyl)morpholine, the preparationof Example 10, at 85-90 C. and the heating and stirring continued for 3hours beyond the terminal addition. The reaction product was dissolvedin commercial hexane and any excess or unreacted was neutralized andwashed out with aqueous 10% NaHCO The hexane extract was washed severaltimes with water, dried and stripped. The elemental analysis of theproduct was C=obs 66.74 (69.36), H=obs 10.69

5 (11.05), N=obs 2.89 (3.32), S=bs 3.27 (2.17), P=obs 1.68 (2.10 percentrespectively.

EXAMPLE 18 The compounds prepared in accordance to the procedures givenin Example 1 through 7 were evaluated as TABLE I Antiwear lubricantproperties of fatty acid amides Avg. wear scar, mm.

Without With Compound additive additive Additive 1 N,N-bis(Z-ethoxyethyDoleamide 0. 597 0. 735 N, N-di-buty1-9,10-epithiostearamide. 2.-. N 0.842 None. 3-.- 0. 623 D0. L 0. 797 Do.5... N, N-di-n-propyloleamide 0. 908 Do. 6 N, N-di-n-hexyloleamide 0.893 Do. 7... N, N-din-butylerucamide 0. 758 Do. 8... N, N-di-n-butylamide of sel. hydrogenated cottonseed fatty acids..." 0. 798 Do. 9... N,N -bis(2-methoxyethyl)oleamide 0. 626 Do. 10.. N, N-dibutyloleamide 0.710 11 N-oleoyl-4-propylpiperidine 0. 847 12.. Morpholide of sel.hydrogenated cottonseed fatty acids. 0. 642 13..N-methyl-N-butyloleamide 0.607 14.. N-ethoxyethoxyethoxypropyoleamlde.0. 503 15. N-ethoxyethoxypropyloleamide. 0. 526 16.-N-methoxyisopropyloleamide- 0. 705 17.- N-methoxyethyloleamide 0. 420 18102 sec paraffin oil N-methoxyethyloleamide. 19 D.0.S Do. 20 N,N-dibnty1-9(10)-carbobutoxyoetadecanamlde-. 0. 610 21 102 sec paraffinoil 0. 818 N, N-dibutyI-9(10) -carbobutoxyoctadecanamide. 22 D.O.S 0.945Do. 23 N-[9 (10) mercapto- (9) IO-dibutylphosphatostearoyllmorpholine.0. 615 24 102 sec paraffin oil 0. 552 N-[9(10)mercapto(9)10-dibytu1phos- D.O.S N, N-dibuty1-[9(1 102 sec paraflin 011.

- D.O.S N, N-dibutyl-Q (10)-[dibutylphosphono1stearamidN-ethoxyethoxyethoxypropyl-Q, 10epithiostearamiN-ethoxyethoxyethoxypropyl-9(10)mercaptostearamide (9, 1042,IS-diepithiostearoyl) morpholine phatostearoyflmofpholine.

0. 498 N, N-dibutyl-[Q(10)-hydroxy-(9)10- d1]b)uty1phosphato]stearamide.

33-. Bis (2-ethy1hexyl) sebacate 34 100 sec paraffin oil 35 Aero Shell(Mil-7808) 36 Gulf Pride, Single G, MS, multiviscosity.

37 100 sec paraflin oil 0. 813 N, N-dibutyl-Q, 10-12,13-diepithiostearamide.

38 Bis (Z-ethylhexyl) sebacate 0. 836 Do.

39 100 sec paraflin oil 0. 723 N-9, IO-epithiostearoyl morpholine.

40 Bis(2-ethylhexyl)sebacare 0. 915 Do.

41 100 sec parafiin oil 0.917 N, N-dibutyl-9, lo-dichloi-osteammide.

42 Bis((2-ethylhexyl) sebacate 0.848 Do.

base lubricants in the Shell Four-Ball Wear tests following a modifiedprocedure of ASTM D2266-67. The resulting scar diameter on the ballsafter running at 600 r.p.m. for 1 hour at 120 C. and kg. load werecompared with the scars obtained using commercial lubricants such asAeroshell Mil-L-70D (di-2-ethylhexyl sebacate and additive), Gulfpride,single G, MS, multiviscosity, and 100 sec. paraffin oil. The results ofthese tests are reported in Table I.

It can be seen from the data presented that the N- alkoxyalkyl andN,N-di(alkoxyalkyl)oleamides, without the assistance of additives,exhibited wear characteristics (i.e., low scar diameters) comparable tothe commercial controls Aeroshell and Gulfpride, which do conatinadditives to improve performance. N,N-dibutyl-[9(10)-hydroxy-(9)IO-dibutylphosphato]stearamide and N-[9 (10)mercapto (9)10dibutylphosphatostearoyl]morpholine not only exhibit low wearcharacteristics in themselves but also impart as additives suchcharacteristics to paratfin oil and DOS base lubricants.

EXAMPLE 19 5 The various amides were evaluated as extreme pressure 7 Theperformance of the amides tested is given in Tables II, III, and IV.

TABLE II Extreme pressure tests (ASTM D2596-67T) Weld point No WithCompound additive 5% #2 1 N,N-bis(2-ethoxyethy1)o1eamide 170 2. NN-di-n-butyl-9,IO-epithiostearamide 300 3.- Ol'eoylrnorpholine 120 4--N,N-dimethyloleam1de 5...- ,N-di-n-propyloleamide 6.N,N-di-n-hexyloleamide-..- 7.- N,N-dl-n-butylerucamide 8 N,N-di-n-butylamide of hydrogenated cottonseed fatty acids.N,N-bis(2-methorryethyl)oleamide N-methyl-N-butyloleamideN,N-dibutyl-Q,IO-epithiostearamide.N,SI-dibutyl-Q,10-12,13-diepithiostearam- 1 e.N-ethoxyethoxyethoxypropyloleamide..- N-ethoxyethoxypropyloleamideN-methoxyisopropyloleamide. N-methoxyethyloleamide N-9IO-epithiostearoylmorphollne- Bist2-ethylhexyDsebacate 100 sec paraflinoil 20 SAE #90 commercial hypoid fluid TABLE III Evaluation ofN,N-d1butyl-9,10-12,13-d1-epithlostearamide as an additive and as a baseoil in extreme pressure tests.

TABLE IIICoutim1ed Extreme pressure tests onN,N-dibutyl-[9(10)-hydroxy-9(10)-dibutylphosphato1stearamide (P C-No.7686) (ASTM D259667 '1) v Applieid Avg. Wear 0a scar, Percent Load, sar, Base 011 Additive gmm. Base oil additive kg. mm.

None 200 0. 887 100 sec parafiin oil (5%) 140 1. 90 No e 300 2. 78 Do(5%) 200 2. None 340 4. 32 -Do (5%) 220 2. 75 None 350 4. .Do (5%) 240 IWeld Non 360 Weld Bis(2-ethylhexyl)sebaeate (5%) 120 l. 51 7686 (5%) 1202. 28 Do (5%) 180 1. 59 (5%) 140 2. 80 Do (5%) i 190 2. 47 6786 (5%) 503. 01 Do (5%) 200 I Weld (5% 160 Weld Do (10%) 240 2.88 7686 (5%) 120 1.95 Do (10%) 260 3. (5%) 140 2. 85 Do (10%) 270 I Weld 7686 (5%) 150 3.03 N,N-dibutyl-e,10-12,l3-diepithiostearam- (5%) 160 Weld ide None120 1. 38

N e 1 0 1, 51 Extreme pressure tests onN-[9(10)-mercapto-9(10)-dibutylphosphato- None 200 1. s9stearoyflmorpholine (O C-O-No. 7687) None 280 2. 13 None 320 2. 47 None120 0. 608 None 360 2. None 160 1. 45 None 400 2. 88 None 200 1. 40 None440 I Weld None 240 1. 70 None 280 7 3. 36

Extreme pressure tests on N ethoxyethoxyethoxypropyl-9,10-epithiostearamide (PC-O-No. 7682) Extreme pressure tests onN,N-dibutyl-9(10)-earbobuty1oxyoctadeeanamide (PC-O-No. 7688) None 1.92.22 2-12 one Additive None 120 Weld 123 i: g c p g e e- None 240 2. 35 a4 g- None 300 2. 19 ggg $832 2&8 iii 30 secondsi None 380 w'eld 5 Teststopped because of extreme decomposition. Did not weld. 7682 2 2 Teststopped because of extreme decomposition and noxious fumes.

(5%) 10 .28 Dunt 1d 7682 (5%) 140 2. 4e 1 we 7682 (5%) 150 Weld 7882(5%) 120 2. 23 7682 (5%) 140 2. 44 7682 (5%) 150 Weld 35 t N th th 11 lTABLE IV Extreme pressure tes s on -e oxye oxyet oxypropy -9 l0Evaluation of N-9 IO-eprthlosteeroyl morpholme as an additive and as amempmteammd" (PC 0 7683) base oil in extreme pressure tests (ASTM D2596-67T) None 200 1. 54 40 Wear 383: Percent Load, scar, Non8 450 a 1Base 011 additive kg. mm. i3}; see paraflin oil 5%) 2. oo Do 57) 2 so7683 (5%) 140 2. 35 7 160 25 7683 (5%) 2. 54 7 180 lw-eld (5%) Weld(579) 80 1 57 7683 (5%) 120 1. 68 7 120 03 7683 (5%) 140 2. 18 7 140 41(5%) 160 2. 59 (57v) 160 94 7683 (5%) 2. 72 7 00 7683 (5%) 180 Weld(59g) 200 :w e 2 1% one 0 Extreme pressure tests on N-(9,10-1213-dlepithiostearoyDmoi-pholine 8 g Do None 380 Weld 0118 None 340 z 43l 10 seconds. 1 5 seconds. 3 50 seconds. None 400 2. 75 None 460 2. 90None 500 v 2. 9s 55 22%; {33 2-2; We claim 0 Egg (2%) 53 g- 3 1. Thecompound N (ethoxyethoxyethoxy)propyl- 57 120 9(10) -mercaptostearamide.2 es .71

5 e ggfi g8 60 References Cited 7 17; 7 wm UNITED 3,746,644 7/1973 Magneet a1. 260-4025 Extreme pressure tests onN,N-dibuty1-9(10)-(dibutylphosphono)stearamide 65 ELBERT L. ROBERTS,Primary Examiner None 120 3.05 None 140 4.50 US. Cl. X.R. None 150 WeldPatent No. 3,801,609 Dated April 2; 1974 Inventcr(s) Frank C. MagneRobert R. Mod, Gene Sum e Ll and w; gfrei Lujarker It is certified thaterror appears in the above-identified patent and that Letters Patent arehereby corrected as shown below:

Column l, line f -l, change "phosphorous" to phosphorus Column 3, line17, change "MN-dibutyloleamlde" to N,N-dibutylllnoleamide l ine 35,change "0.75 moles" to 0.73 mole l ine 35 change "0.72 moles" to 0.73mole I Column l ine-53, change "10 to 10% a Column 6, line 2 change"p.p.m." to RPM line change "ran" to run- Signed and sealed this 21stday of January 1975.

(SEAL) Attest:

McCQY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents

